Calorimetry is increasingly an important method not just for synthetic materials and industrial processes, but also for biological and pharmaceutical applications. For example, isothermal titration calorimetry (ITC), including both differential scanning calorimetry (DSC) and thermal shift assays (TSA) (also, known as Differential Scanning Fluorimetry (DSF)), conventionally refers to a family of techniques for probing various thermal-related properties of, for example, chemical reactions, biomolecules, or biological species. ITC is used in a variety of scientific fields, including but not limited to proteomics, genetics, molecular biology, and drug discovery. DSC can measure, for example, heat capacity at different temperatures. TSA can measure, for example, an interaction between a fluorescent probe and a sample.
Current ITC technologies, however, can be prohibitively costly in terms of speed, sensitivity, and required amounts of sample. Major challenges to devising high-performance microcalorimeter devices include, among other things, maintaining heat retention and providing isolation from environmental disturbances. Further, as reaction volume decreases, heat production and therefore signal reduces proportionally, thereby adversely affecting miniaturization efforts for DSC and TSA technologies.
To date, employment of DSC and TSA at the microscale has been extremely limited due to the shortcomings of present instruments in throughput and operation costs. Furthermore, conventional DSC instruments do not offer the ability to also perform TSA measurements, and current TSA instruments do not offer the ability to also perform DSC measurements. Hence, a need exists for better devices and methods.